Novel technique for isolation of human lung mast cells

A novel technique for isolation of human lung mast cells is developed. Human lung tissue was enzymatically digested and the cells were partially purified by centrifugation on Percoll density gradient. Cells obtained at the Percoll density of 1.05-1.09 g/ml were then subjected to a cell sorter equipped with a single argon laser beam (FACS 440). Using four criteria as density, granularity, size and autofluorescence, four major cell populations were identified. One of the major populations contained 70-95% mast cells with a mean and SE values of 88 +/- 11% purity, n = 18 as determined by the measurement of total histamine content, light microscopic observation of stained cells with toluidine blue and estrase, and surface-stained IgE fluorescence antibody. Approximately less than 10% mast cells were identified in the three other major cell populations. Mast cells isolated by FACS were found to be intact, viable (approximately equal to 90%) and functionally normal as determined by the release of histamine evoked after stimulation with ionophone A23187, or challenged with anti-human IgE.